Ossipee — August 22, 2006 — Officials are asking boaters to be wary of flags signaling divers are toiling in the depths of Ossipee Lake. In a war on weeds, frogmen in scuba suits will be tearing up bagfuls of invasive milfoil from below the waterline in infested Phillips Brook, parts of Leavitt Bay and all of Portsmouth Cove.

As expected, after a first harvest last year some of the town’s worst unwelcome transplants have come back. The tangled, mud-layered Phillips Brook has shown about a 25 percent resurgence in invasive milfoil. The regrowth rate of the stifling interloper dipped to 5 percent where the inlet feeds into Leavitt Bay, according to a report by the Ossipee Lake Alliance.

In a progressive state pilot program that aims to find out if divers can outperform herbicidal chemicals, New England Milfoil, and company founder, Cliff Cabral, have literally worked in deep muck. In the last three years, eight tons of the tall thin trespasser were torn by Cabral and his crew from Freedom’s Danforth Pond. From June through Labor Day of last year, five more tons of aggressive sprouts were dragged out of Ossipee Lake, according to the report by the lakefront homeowner’s group.

The Alliance and the town of Ossipee together earned a grant from the state to match the $10,000 the town set aside to go to war with the wiry weed. Susan Marks, representing the Alliance, was optimistic about last year’s results, but cautioned that it will be years before officials can accurately gauge divers’ effectiveness.

Marks also encouraged storefront homeowners in coming weeks to collect and destroy plant pieces that wash up on beaches. Most importantly, boaters are urged to use caution near flags and give divers a wide berth.